EQ1- the water cycle

Question 1

5.1a Is the drainage basin a closed system?

Answer 1

yes

Question 2

5.1 aHow does solar and gravitational potential energy drive the hydrological cycle?

Answer 2

gpe- causes precipitation to flow downhill and precipitation to fall to ground
solar- in the form of heat

Question 3

5.1 b What percentage of the global water supply do the store of oceans contain?

Answer 3

97%

Question 4

5.1 b What percentage of the global water is freshwater?

Answer 4

2.5%
- 69% of this is glaciers, ice caps and and ice sheets
- 30% is groundwater

Question 5

5.1c What is the hydrology in Polar regions?

Answer 5

• 85% of solar radiation is reflected
  ▪ Permafrost creates impermeable
  surfaces
  ▪ Lakes and rivers freeze
  ▪ Rapid runoff in spring
  ▪ Seasonal release of biogenic gases into
  atmosphere
  ▪ Orographic and frontal precipitation

Question 5

5.1 b what percent of global stores are surface and other freshwater?

Answer 5

1%
- Other surface and freshwater is made up of ​permafrost, lakes, swamps, marshes, rivers and living organisms​.

Question 6

5.1c What is the hydrology in tropical rainforests?

Answer 6

▪ Dense vegetation consuming 75% of precipitation
▪ There is limited infiltration
▪ Deforestation leads to less
evapotranspiration and precipitation
▪ Very high temperatures
▪ Very humid
▪ Convectional rainfall

Question 7

5.1 c water are the different water stores’m residence times? (oceans, icecaps, groundwater, rivers+lakes, soil moisture and atmospheric moisture)

Answer 7

Oceans- 3600 years
Icecaps- 15,000 years
Groundwater- 10,000 years
Rivers and lakes- 2 weeks to 10 years
Soil moisture- 2-50 weeks
Atmospheric moisture- 10 days

Question 8

5.2 a What is the only input in the drainage basin?

Answer 8

Precipitation

Question 9

5.2 a How does the type of precipitation impact the drainage basin hydrological cycle (input)?

Answer 9

• rain, snow or hail
• The formation of snow can act as a temporary storage and large fluxes of water can be released into the system after a period of rapid melting, resulting from thaw

Question 10

5.2 a - How does the amount of predication impact the drainage basin (input)?

Answer 10

• Has a direct impact on drainage discharge
  general rule: the higher the amount, the less variability in its pattern

Question 11

5.2 a How does seasonality impact the drainage basin (input)?

Answer 11

• in some climates, such as monsoon, mediterranean or continental climates there are strong seasonal patterns of rainfall and snow
• These have a major impact on the physical processes operating in the drainage basin

Question 12

5.2 a How does intensity of precipitation impact the drainage basin (impact)?

Answer 12

Major impact on flows on/belo the surface.
- Difficult for rainfall to infiltrate if is very intense as soil capacity is exceeded

Question 13

5.2 a What are the three different ways variability can be measured? (input)

Answer 13

Secular- long term, e.g as a result of climate change trends
Periodic variability- happens in an annual, seasonal, monthly or diurnal context
Stochastic- results from random factors e.g, the localisation of a thunderstorm in a basin

Question 14

5.2a How does the distribution of precipitation within a drainage basin?

Answer 14

• particularly noticeable in v large basins such as the NILE
• tributaries start in different climatic zones
• At a local scale +shorter time scale, the location of the thunderstorm within a small river basin- major impact temporarily

Question 15

5.2.a What is convection rainfall and how does it occur?

Answer 15

• common in tropical areas and the uk during summer
• land becomes hot- air above expands and rises, cools and condenses, if continues to rise, rain will fall.
• further ascent, more expansion+cooling-rains
  1) earth’s hot surface heats air above it
  2) heating air rises, cools, expands and cools- condensation takes place,
  3) cumulus cloud forms
  4) cold air descends and replays warm air

Question 16

5.2.a What is cyclonic rainfall and how does it occur?

Answer 16

• Occurs when warm air (lighter and less dense) is forced to rise over the cold, dense air- cools and condenses- rains
• cumulus cloud is formed in the process

Question 17

5.2.a What is Orographic rainfall and how does it occur?

Answer 17

• when air is forced to rise over a barrier, e.g, mountains- cools and condenses- forms rain- leeward (downward) slope has relatively little rain (heavier rain on higher land, peaks)
• known as the rain shadow effect

Question 18

5.2.a What is interception?

Answer 18

• The process in which water is stored In vegetation

Question 19

5.2.a What are the main components of interception?

Answer 19

• Interception loss
• throughfall
• stemflow

Question 20

5.2.a How do meteorological conditions have an impact on the drainage basin? (storage, interception)

Answer 20

• Wind speeds can decrease the interception loss as intercepted rain is dislodged
• Can also increase evaporation rates

Question 21

5.2.a How does interception loss impact the drainage basin? (storage)

Answer 21

• Interception loss from vegetation usually greatest at the start of the storm, especially when follows a dry period
  Interception capacity varies with the type of tree:
  coniferous trees- dense needles, greater accumulation of water
• There are also contrasts between deciduous forests in summer Vs winter

Question 22

5.2.a How does